sibilate vs say

sibilate is not a noun while say is a noun.

Word	Noun	Adjective	Verb	Adverb
sibilate	No	No	Yes	No
say	Yes	No	Yes	No

As verbs, say is a hypernym of sibilate; that is, say is a word with a broader meaning than sibilate:

Other hypernyms of sibilate include articulate, enounce, enunciate, pronounce, sound out.

sibilate (noun)	say (noun)
	the chance to speak

sibilate (verb)	say (verb)
make a sharp hissing sound, as if to show disapproval	express in words
express or utter with a hiss	report or maintain
utter a sibilant	speak, pronounce, or utter in a certain way
pronounce with an initial sibilant	express a supposition
	give instructions to or direct somebody to do something with authority
	communicate or express nonverbally
	recite or repeat a fixed text
	indicate
	state as one's opinion or judgement; declare
	utter aloud
	have or contain a certain wording or form